Stainless Steel Chimney Liners vs. Aluminum Chimney Liner

When it comes to relining your chimney, all of the options can be overwhelming. There are so many choices out there, from the type of metal flue liner you choose to the thickness and rigidity of the pipe. It is difficult to decide exactly what option is best for you. On the market today are kits, stainless steel chimney liner kits and aluminum chimney liner kits designed to make the process a little bit easier, but even these can be difficult to understand. These kits most often come with all of the pieces needed to properly line a chimney including insulation and a chimney cap.

There are two main types of metal pipe you can line your chimney with, aluminum and stainless steel. There are many alloys of stainless steel, but we will get into that later. When lining wood burning stoves or wood burning fireplaces, you must use stainless steel. Almost all stainless steel liners that have been UL listed require insulation in the form of a blanket or poured insulation material, and it is recommended that aluminum liners be insulated as well. Aluminum is not appropriate for wood burning appliances or fireplaces because of the temperatures that the fires reach when burning wood.

Metal chimney liner's efficiencies are improved when insulated.

316 stainless steel pipe is a Ti-alloy of stainless steel that can be used to vent wood, pellet, coal, oil, and noncondensing gas burning appliances or fireplaces. This alloy is easy to handle and installs more quickly than regular stainless steel pipe. It is also known for its corrosion resistance in acidic environments and its ability to resist high heat corrosion.

Aluminum is the ideal gas chimney liner. It has been the material of choice for venting gas fired appliances for more than half a century. You want to make sure to purchase a liner that is UL listed. This means it has been put up to standard tests and passed. Many liners come with a lifetime warranty when installed by a professional when installed according to the manufacturers instructions.

Can aluminum chimney liners be used in a clay tile flue that was previously an oil boiler system, but has been a gas boiler system for the past 40 years? A contractor told me that because an oil fired boiler was used previously that I could not use an aluminum liner! Another contractor said I could use an aluminum liner? Who is correct?

I can’t be the judge in the matter of the two opinions, but what I will say is “What do the boiler MFG say in their instruction manual in regards to their venting requirements.” This is important in deciding what to do because all of this equipment is UL listed to specific standards. I would no use an aluminum liner with a boiler nor would I put aluminum liner in any liner that was used for oil at any time. Also be very cautious of the grade of stainless steel that would be used on the interior. Be sure that the stainless steel pipe has specific properties that resist acetic oil bi-products. Install according to the manufactures instructions ONLY, not opinions.